> There were heaps of problems in there and it is surprising how few people> were hitting them. Ordered-mode journalling filesystems will fix it all up> behind the scenes, of course.> > I just have a bad feeling about that code - list_heads are the wrong data> structure and it all needs to be ripped and redone using some indexable> data structure. There has been desultory discussion, but nothing's> happening and nothing will happen in the medium term, so we need to keep> on whapping bandainds on it.

The reason why I'm looking at that code is because of thosebalance_dirty_pages() deadlocks. I'm not perfectly happy with theper-pdi-per-cpu counters Peter's patch is introducing.

I was wondering if we can count the number of writeback pages throughthe radix tree, just like we do for dirty pages?

All that would be needed is to keep the under-writeback inodes on somelist as well.